This invention relates generally to method employed and apparatus used in conjunction with disposal or cleaning of coolant used in internal combustion engine cooling systems. More particularly, it concerns safety apparatus for relieving fluid pressure build-up in radiators from which coolant is to be removed for disposal or external treatment, including cleaning of the coolant, or to enable coolant system repair.
Studies show that over-heating is a major cause of vehicle breakdown on highways. Engine cooling systems must operate efficiently at all times to avoid costly repairs that result from excessive temperature. In this regard, cooling systems contaminated by rust, scale build-up and sludge cannot provide adequate heat transfer and cooling system efficiency; in addition, thermostats fail to open, hoses deteriorate, impellers bind or break off, and engine blocks can become distorted or crack. Accordingly, there is a need for efficient engine cooling system flushing methods and apparatus; however, flushing of such systems in the past required draining of the removed liquid to sewer or waste lines, which was environmentally objectionable. Accordingly, need has developed for apparatus and method to clean engine coolant systems without such drainage.
U.S. Pat. No. 5,078,866 to Filowitz et al. discloses apparatus and methods for externally treating coolant liquid removed from an engine coolant system. The coolant to be treated is typically removed from the radiator unit associated with the cooling system, and typically via the radiator fill port, after the radiator cap is removed. However, removal of the cap is dangerous when pressure build-up has occurred in the radiator, since the worker can be scalded by steam and hot liquid, if the cap is not properly removed.
There is need for method and means to alleviate this danger, prior to coolant liquid removal for disposal, transfer, inspection, or treatment and return to the coolant system.